Blueberry Gall Midge Control

L. K. Tanigoshi, B. S. Gerdeman & G. Hollis SpitlerWSU Mount Vernon Northwestern Washington

Research & Extension CenterDept. of Entomology

Budbreak through Bloom Management:Blueberry gall midge, Dasineura oxycoccana Larvae legless, 1 mm

long, white-orange incolor.

Eggs laid in floral orvegetative buds afterbud swell.

Buds abort andblackened young shoottips, distorted leaves.

Late season ‘witchesbroom symptoms.

4-5 generations/year.

Blueberrygall midgelays eggs inside terminals, 0.35mm long, hatch in 2-3 days.

Blueberry gall midge 1st & 2nd instar larvae are white andbegin to turn orange as they approach 3rd instar. 1-2 mm. long

7-8 day larval period

Blueberry gall midge prepupae(left) and pupae (right), 3-4 days.

BGM pupatesin a cocoon in the soil.A cocoon has been opened toreveal the pupa.

Witches broom

Female

Puparium Emergence trap

Yang

Male

Yang

Yang

Newly emerged female blueberry gall midge adult, 2-3 mm long.

Live 4-6 days

Characteristic of BGM infestation is aborted and/orblackened young shoot tips and distorted leaves.

Witches’ broom increases labor costs, poor bud setand may reduce berry size.

Monitoring Methods

Chemical, Cultural, Biological Control: BGM listed on Delegate label. Legal uses of: Actara, Admire, Assail,

Platinum, Provado, Diazinon, Malathion,Mustang, Lannate.

Prebloom malathion resulted in 94%mortality in 24 hrs, SE US, Sampson/USDA.

Cultural control, none known. Biological control, new species of parasitic

wasps.

Dormant and PreBloom PeriodsBGM overwinter in the soil as pupae,

emerge as adults in March.

Blueberry gall midge field trial, Lynden, WA,2008

Movento (spirotetramat), Group 23 MOA, lipid biosynthesis inhibitor (LBI). 2 way systemicity in host plant. Active by ingestion, primarily sucking

insects (aphids, whiteflies, scales,mealybugs).

IGR activity, reduced fecundity (egglaying) and survivorship of offspring.

Not registered on small fruits, Bayer CS.

DPX-E2Y45, (chlorantraniliprole), Class 28 MOA, binds to insect ryanodine receptors, causing

uncontrolled release and depletion of Ca++. Prevents muscle contraction, paralysis, stops feeding,

lethargy and ultimately death. Ingestion stops feeding within minutes. Active on eggs (ovicidal) and larvae (ovi-larvicidal). Translaminar activity and rainfast. Highly effective on caterpillars, some beetles, and flies. No cross resistant to insect populations resistant to other

classes of insecticides. Selective to predators, parasitoids and pollinators.

Blueberry gall midge bioassay, 2008

Blueberry gall midge bioassy, 2008

Summary

4-5/6 generations a year in the PNW,seemingly associated with flushing periods.

Overwinters as a pupa, emerging in earlyMarch. Prebloom drench tactic.

Foliar windows for multiple insecticidesare prebloom and postharvest periods.

New mode of action chemistries are veryeffective, including experimentals beingevaluated.

Current BGM Studies for 2009

Continue terminal sampling of vegetativeand floral buds to determine infestationrates.

Understand economic impact of BGM onbranching patterns, bud set and berry sizeof current year’s wood.

Couple terminal sampling with foliar anddrench treatments.

Please carefully note that Movento,DPW-E2Y45 and Gnatrol are notEPA registered for their use onblueberry. As with any crop-

protection product, always readand follow label instruction.

Acknowledgements

Washington State Blueberry CommissionNorthwest Agriculture Research Foundation

B. S. GerdemanG. H. Spitler

Wei YangC. Meckstroth

L. HirdlerJ. Flores